Method of deodorizing and filtering oils



Jann 3, V. C. BENJAMIN METHOD OF DEODORIZING AND FILTERING OILS Filed Sept. 29. 1925 Relief Utr/IMA 2 y-aos pipe,

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lPATENT OFFICE.

VICTOR C. BENJAMIN, 0F LOS ANGELES, CALIFORNIA.

METHOD OF DEODORIZING AND FILTERING OILS.

l 'Application led Septemliei` 29, 1925. Serial No. 59,288.

This invention has to do with deodorizing hydrocarbon and other oils, Where the treatment used for the purification of such oils causes decomposition that induces odor in the treated products.

`As aninstance of the application of the invention, lf may state the following: ln the treatment with adsorbent clays (solids) of lubricating stocks from petroleum oils it has been found either desirable or necessary to carry the treating temperatures fairly high. For instance, in an average case the finishing temperature of a lubricating oil may be as high as 650 F., though clay treatments may be eectively carried out at lower temperatures. At such a temperature the more volatilehydroearbons undesired in a lubricating oil are driven off and it is found that the eciency of the adsorbent clay used in the treatment is much increased. 'lhus it is desirable to treat such lubricating oils at comparatively high temperatures in order to produce a clear final product. But it has been found that such high temperatures, particularly when the oil is used with nely divided clay, induces decomposition that causes oil to have an undesirable odor; and it is among the objects of this invention to provide a simple .procedure for removing such odor.

Without thereby placing a limitation upon my present invention, I may easily explain it in connection with such a process as is described in my application entitled Process -of purifying) oils, Serial Number 737,444,

filed Septem er 13, 1924. In that process I treat a lubricating stock, such as an original stock or a used lubricating oil, by gradually bringing it up to the desired finishing temperature, keeping it in constant agitation during the period of heating, taking off the vapors during the heating, and then finally filtering the treating clay and all filterable impurities from the remaining liquid. During the Whole of the heating period the clay in finely divided form is admixed with the I oil. During a part, at least. of the heating period, as explained iu said application, I agitate the oils by passing steam through them, the steam also servino' to carry away volatile impurities. Then, 1n that process,

Vll explain how steam circulation is shut off at the finish of treatment and the oils are then ltered. After steam circulation is shut oft and during the filtering operation the oils are still at high temperature (being preferably filtered at least at a fairly high temperature), and are in contact with the clay until filtration is completed9 but are not in contact With the steam.

l have found that by keeping the live steam in intimate contact With the oils until the filtering operation is completed, steam carries away from the oils all the odorous products of decomposition, and then, after filtration and consequent removal of clay, contact of steam may be cut 0E, as no more odorous decomposition is then taking placeo lin order to describe more specifically a preferred and illustrative procedure in accordance with my invention, l have shown diagrammatically in the accompanying drawings a simple form of apparatus that will suffice.

In giving this description I shall not attempt to go into all of the details of the preferred form of process of treating the oils to get rid of their lighter constituents, or many other details Which are not necessary here to a clear understanding of the present invention. lt will sufce to say that in the treatment of oils they are placed in treatment tank 10 in admixture with the proper amount of tinely divided adsorbent clay. Several such clays are Well known in the art and need no particular description here. Their property is to adsorb to themselves the impurities in the oil so that thosel impurities may finally be filtered out with the clay. The mixture of oil and treating clay is put into treatment tank 10 toa suitable level, and is brought up to suitable treating and finishing temperature by any suitable heating means, as by a heater l2. During this heat treatment the vapors pass ofi' through vapor line 13 to condenser 14, and durino this heat treatment be kept agitated by any suitable means, and preferably are kept agitated, at least during the latter part of their rise in temperature,

by steam that may be introduced from steam line 15 through branch line 16 and the main oil pipe 17 that leads into the bottom of the treatment tank, the steam being under control of valve 18. Thus during the treatment -of the oils at comparatively high temperatures (say up to a maximum of 650O F.) live dry steam' is being continuously blown 'through the oils to keep them agitated and this steam also has the function of assisting the oils may to carry away the vapors of volatilehydrocarbons and also carries away with it all theodorous decomposition products formed during theheat treatment.

When the heat treatment is completed, then, instead of shutting off the steam from the oil during the final filtering, I keep the steam passing into the body of oil through pipe 16 during the time that the oil is passing out through pipes 17 and valve 19 to lilter 20. A certain amount of steam is entrained in fine division in the oil and is carried down with the oil to the filter so that the oil in the filter carries steam with it and remains in intimate contact with the steam. During this filtration valve 21 is closed in order to build up steam pressure in treatment tank 10 and filter 20, provision being made to relieve eXcess pressure through re 43 lief valve 22 and thence through by-pass pipe 23 into condenser 14. It is thus evidentthat as filter cake 2Ot builds up in the filter 2O and oiers increasing resistance to flow of oil into line 24 there Will be automatic increase of pressure within the treatment tank 10 and the filter 20 and that such increasedv pressure will be controlled by steam pressure in line 15 together with regulation oit relief valve 22. The filter may be of any suitable type that will not trap steamthat is a iilter of any type that will pass the steam through it along with the -oil--so that the steam remains in intimate contact with the oil until the oil is entirely clear of all the clay and other lterable impurities.` It is esssential that the steam pass in intimate admixture through the lter with the oil without separation; and for that purpose I make the piping tank to the filter such as not to separate or trap steam, and I choose a type of filter that does not induce steam separation. For instance, a filter having a horizontal filtering medium 20 operates well, as there is no ten-` dency for the steam to rise along the filtering element as would be the case with a vertical element.

The oil and steam together pass from the filterv throu h line 24 to any suitable separator 25 w erein, by-reason of the enlarged capacity of 25 as compared to'line 24, the ve vco ocity of the oil and steam stream from line 24 is retarded and thesteam is thus 'ven ample time to separate from the oil and escape through line 26 into condenser 27. The oil in 25, being now freed of steam, Hows through line 28 to cooler 29, thence through pipe -35, which is so bent or constructed as to retain the oil in cooler 29 at sufiiciently high level to prevent any flow of steam from separator 25 through t e cooler, and valve 36 to oil storage, valves 37 and 38 being closed. Should moisture show in oil after cooling in cooler 29 the How through line 35 can be diverted to blowing tank 39, by closarrangements from the treatment Y ing valve 36 and opening valve 38, wherein it can be blown with air introduced through line 46 and valve 40, valve 41 being closed. After having been blown dry the oil can be run to storage through valve 41 and line 42, valve 40 being closed. If it is desired, vacuum may be applied to condenser 27 and therefore to line 26 to facilitate the drawing' olf andseparation of the steam from the oil.

The pipe 28 extends into and above the bottom of separator 25 in order to provide against any condensation of steam which might occur in 25 overiowing into line 28, it being quite obvious that should such condensation occur the Water .thus occasioned would immediately settle to the bottom ot the separator 25. and from thence can be drawn off, from time to time, through valve The procedure here described shows how the steaml is kept in intimate contact with the oil until filtration is completed. This procedure is particularly applicable to hot filtration, which in itself' is desirable.

Leading from steam line 15 I show another branch line 44 controlled by valve 45 which leads to the oil l'ine'17 below valve 19. This steam line is supplied for the purpose of insuring the oil passing to the filter being in contact with a suiiicient amount of steam toabsorb and finally carry away all odorant that may be formed, in event valve 19, for any reason, should be closed thus cutting off ow of steam into filter from line 16.

It will be apparent to those skilled in this art, that various modifications both of procedure and of apparatus may be used. I describe only one type of apparatus merely for the purpose of clearly illustrating a suitable means for the carrying out of my process.v The apparatus used need not be in the form illustrated, as apparatus of dif.- ferent construction may be used, provided such construction embodies means for carrying out the essential steps of this invention. These essential steps are: First-to heat the oil to a suitable temperature with a suitablev adsorbent material in the presence of steam for the carrying away of decomposition products; secondmaintaining the oil in agitation with the solid adsorbent during a sufcient time to allow the adsorbent to expenditself in purifying the oil; and thereafter to pass the oil and spent adsorbent in intermixture with steam through a filter of such construction as will not permit the steam and oil to separate within such filter,

and at a temperature suiiiciently high to prevent the condensation of steam; and finally--to remove the'steam from the filtered oil after separation of the oil from the spent adsorbent. In other words, the method con- Y templates keeping steam in intimate'contact with the oil throughout that period during which the heated oil is in contact with the clay, or that period in which the formation of odorant takes place.

1. In the separation of spent adsorbent from highly heated oils in a closed filtering system under pressure on the inlet side, said system having a foraminous filteing medium, the step comprising: simultaneously passing through the foraminous medium a flow of steam and a flow of highly heated oil containing spent adsorbent, said steam being entrained in said oil during said passage; and retaining said adsorbent on said medium, thereby separating it from said oil and entrained steam.

2. In a method involving the treatment of oils with adsorbent, bodies at high temperatures, in a substantially closed Vessel, and

. the subsequent separation of the spent ada closed filtering system sorbent from the oil at high temperature, in 20 ent, together with `steam entrained therein,

against the foraminous medium; retaining said adsorbent on said medium and thereby separating it from said oil and steam; passing said oil and the steam entrained therein through said medium and through the layer of adsorbent collecting thereon, and finally separating said steam, without condensation thereof, from the adsorbent-free oil.

-In Witness that I claim the foregoing I have hereunto subscribed my name this 17th day of September, 1925.

VICTOR o. BENJALHN. 

